UE i el EEO emer n tab tinip tell o-4 to Ph Rae Bathe A, CLES ee ee - : ae D CR ST 2 (2k EO O RESELL SPINE LY PTET os PS ene aR A en oan + bc AA Om Bait Pee E EE ae Lar its eer oe oes a oe ae + ee a ae ate 4 hire ‘ hes tar Peet oa eed va id 7 ~ ‘ ne 4 oe ds pease A A we a a ln hat 2S es tS 8s Sat med 8 nA rs etre heobalyeat. wie pt preege 4 Sofas Tae Fe om SON ea ar aye Oh AD OD AE SOR Oe AEE LIA 9 SU PRS ERIN ET OP PS ay a yt at ae.” yee re Ube pent Dann apne bre peremeet a Ni y Ne BRYOZOA OF THE ALLAN HANCOCK ATLANTIC EXPEDITION, 1939 By RAYMOND C. OSBURN THE UNIVERSITY OF SOUTHERN CALIFORNIA PUBLICATIONS ALLAN Hancock ATLANTIC EXPEDITION REPORT NUMBER 5 IssUED OCTOBER 31, 1947 Tue UNIVERSITY OF SOUTHERN CALIFORNIA PRESS Los ANGELES, CALIFORNIA BRYOZOA OF THE ALLAN HANCOCK ATLANTIC EXPEDITION, 1939 (PLATES 1-6) RAYMOND C. OsBuRN RESEARCH ASSOCIATE ALLAN HANCOCK FOUNDATION During the month of April, 1939, with the Velero III, a collecting expedition was made into the Caribbean Sea. The full details of the expedition are given in the account by Dr. John S. Garth, “Geographical Account and Station Records of Velero IIT in Atlantic Waters in 1939,” Allan Hancock Atlantic Expedition Report Number 1. The course of the cruise was from the Panama Canal eastward along the coasts of Panama, Colombia, and Venezuela as far as the islands of Trinidad and Tobago, and returning over much of the same course. The dredging was all done on the coastal shelf, 71 fathoms being the deepest haul. Much of the bottom in this area consists of sand and mud which are usually unfavorable to the development of a rich attached benthic fauna. Since ecological conditions apparently did not vary to any great extent, the list of 107 bryozoan species is unexpectedly large. Very little such collecting has been done in this region and the records are therefore of special interest for distributional studies. The only paper dealing with the Bryozoa within this area is an account by the writer (Osburn 1927) of 23 species taken at Curacao Island by Dr. C. J. van der Horst (Bijdragen tot de Kennis der Fauna van Curacao. Resultaten eener Reis van Dr. C. J. van der Horst in 1920). Dr. van der Horst’s collections were all made in shallow water about the harbors of Curacao. The first important work on the Bryozoa of the general West Indian area was that of Smitt, the Swedish naturalist, who studied and reported on the collections made by Count L. F. de Pourtales in the region of southern Florida (Smitt 1872 and 1873). In 1908 Osburn collected Bryozoa about the Oceanic Laboratory of the Carnegie Institution at the Tortugas Islands, Florida, (1914), and in 1927 reported on a col- lection made by van der Horst at Curacao. In 1928 Canu and Bassler published an important paper on the collections made, especially by the Albatross, in the Gulf of Mexico, Florida Straits and vicinity. This was followed by Osburn’s report on his collections in the vicinity of Porto C1] 2 ALLAN HANCOCK ATLANTIC EXPEDITION REPORT Rico. As a result of these studies about 230 species have been recorded for this general area, but, except for the brief report on Curacao, the Bryozoa of southern Caribbean coastal shelf are unrecorded. The present account adds 14 species to those already known to occur in the West Indian area and 7 of these appear to be new and are described and figured. As only 23 species have hitherto been known from the southern coast of the Caribbean Sea, the present work adds 84 to this region and is further important in that a number of these are rare and have been recorded elsewhere only once or twice. “—ITwo common Pacific species have been added to the Atlantic fauna. It is well known that many of the tropical species are circumtropical in distribution and may be found almost anywhere in warmer waters. Thus 44 species of the present list are known from the Pacific coast of the Americas, and most of these have also been recorded from the Eastern Atlantic, Western Pacific and Indian Oceans. The writer desires to express his thanks to the Allan Hancock Foun- dation of The University of Southern California for financial assistance during the progress of the work; to Dr. Irene McCulloch and her staff of assistants for aid in many ways, and to Mr. Anker Petersen, Staff Artist, for his careful work in preparing the illustrations of new species. BRYOZOA Ehrenberg 1831 ENTOPROCTA Nitsche 1869 Family Pedicellinidae Johnston 1847 Genus PEDICELLINA M. Sars 1835 Pedicellina cernua (Pallas), 1771 Osburn 1914: 212; 1940: 326. Widely distributed; along the eastern coast of the Americas it has been recorded at numerous places from Nova Scotia to Santos Bay, Brazil (Marcus 1938:5). Osburn has noted its occurrence in the West Indian region at the Tortugas Islands and Porto Rico. The variations in the number of minute spines on the stalk and calyx has led to the erection of several nominal varieties. In the present col- lections some individuals have no spines, some have a few on the stalk, but none have spines on the calyx. Distribution—Station A30-39,1 Cubagua Island, shore, a few colonies on A mathia stems. 1 This study involves two station lists: A stations refer to the regular Atlantic station list and At stations refer to the bottom sample station list. In this report the word “Distribution” is limited to a summary of the stations involved in this particular investigation. g No. 5 OSBURN : BRYOZOA 3 Genus BARENTSIA Hincks 1880 Barentsia discreta (Busk), 1886 Osburn 1914: 185; 1940: 327. In this species the chitinous stalk appears to have numerous pores, which in reality are only in the internal stalk layer. It is circumtropical in distribution, extending also into temperate waters. Osburn has recorded it from the Tortugas Islands and Porto Rico. Distribution.—Station A30-39, 2 miles SW of Cape la Vela at 21 to 22 fms, a few colonies. ECTOPROCTA Nitsche 1869 Cyclostomata Busk 1852 Family Crisiidae Johnston 1847 Genus CRISIA Lamouroux 1812 Crisia elongata Milne-Edwards, 1838 Osburn 1940: 328. A circumtropical species, recorded by Osburn off the mouth of Guanica Harbor, Porto Rico. Distribution.—Station A18-39, 8 miles SW of San Nicolaas Bay, Aruba Island, at 24 fms. Family Oncousoeciidae Canu 1918 Genus ONCOUSOECIA Canu 1918 Oncousoecia arcuata Canu and Bassler, 1928 Canu and Bassler 1928: 158. Ten specimens of this linear encrusting species were found on coral- lines and shells. All of the zoaria are very small, the longest only 4 mm, but the colonies less than 2 mm in length were in reproduction. It has been previously recorded only by Canu and Bassler at the type locality, Albatross Station D. 2639, Straits of Florida. Distribution.—Station At505, Aruba Island at 23 fms. Genus PROBOSCINA